While sales of many big SUVs are dipping, Hummers are rumbling out of showrooms at a rate of 3,000 per month, topping the list of best-selling large luxury SUVs in the U.S., despite a starting price of $50,000. Some buyers say they feel patriotic in a massive Hummer H2, the civilian sibling of the military Humvees now doing active duty in Iraq, and Hummer dealers report that sales have risen with the war. “When I turn on the TV, I see wall-to-wall Humvees, and I’m proud,” said H2 owner Sam Bernstein. “They’re not out there in Audi A4′s.” The Sierra Club is ramping up for a campaign against Hummers, which are so large and heavy that they are exempt from the fuel-economy rules that govern cars and regular SUVs. “At a time when our troops are at risk in part because of our oil dependence, it is the height of irresponsibility for General Motors to be pushing an 11-miles-per-gallon gas guzzler,” said the Sierra Club’s Daniel Becker.